WEDNESDAY, Dec. 21 (HealthDay News) -- Life expectancy is a topic many disabled seniors want to talk about with their doctors but very few have that discussion, a new study finds.

It included 60 elderly patients with an average age of 78 who had multiple illnesses and disabilities and lived in a community-based, long-term care program in San Francisco. None of the patients had been diagnosed with a specific terminal illness.

Interviews with the patients revealed that 75 percent would want a conversation about their prognosis if their doctor felt they had less than a year to live, while 65 percent would welcome such a dialogue if they likely had fewer than five years to live.

However, only one of the 60 patients reported having such a discussion with a doctor, said the researchers at the San Francisco VA Medical Center and the University of California, San Francisco.

Wanting to prepare for death, making the most of their remaining time and making medical or life decisions were among the most common reasons the patients gave for wanted to discuss their prognosis.

"When physicians bring up prognosis, it's usually thought of as a health issue, but for the person on the receiving end, the conversation is about a lot more than that," lead author Cyrus Ahalt, a geriatrics research coordinator in UCSF's Department of Medicine, said in a university news release.

"We've made big strides in changing the way that doctors communicate prognosis to patients who have cancer, organ diseases or other terminal diagnoses, but this study shows that we still have room to grow in discussing life expectancy with frail older adults who have poor prognosis simply because of multiple physical or cognitive impairments or old age," added principal investigator Dr. Alexander Smith, a physician at SFVAMC and a bioethics expert and assistant professor of medicine in the division of geriatrics.

The study was published online Nov. 30 in the Journal of General Internal Medicine.